A magnetic random access memory (MRAM) device is a memory device that comprises a plurality of memory blocks, termed as MRAM blocks. Each MRAM block has word lines, bit lines, and memory cells, referred to as MRAM cells. The MRAM cells are used to store data and lie at intersections of word lines and bit lines.
In an MRAM device, there is a limit on the amount of data that can be written to the MRAM device since the MRAM device usually has a limited number of small-sized MRAM blocks or a limited number of large-sized MRAM blocks. The MRAM device has a limited number of large-sized MRAM blocks since usually a high value of write current drive voltage is required to write to large-sized MRAM blocks and cumulative read currents produced by consecutively reading from large-sized MRAM blocks interfere with reading from the MRAM blocks. A high value of write current drive voltage is usually required since the write current is fixed and large-sized MRAM blocks have high resistances which cause the high value of write current drive voltage to reduce as the MRAM blocks are written. Reading from large-sized MRAM blocks interferes with the read operation since consecutively reading from a large number of large-sized MRAM blocks generates a large amount of current that interferes with the read operation.
The MRAM device has a limited number of small-sized MRAM blocks since each small-sized MRAM block has peripheral circuitry that occupies a large amount of area on the MRAM device, thereby reducing any available area for the MRAM blocks. The peripheral circuitry typically includes decoders and drivers at each edge of a small-sized MRAM block. Hence, in an MRAM device, there is a limit on the amount of data that can be written to the MRAM device.
From the above, it can be appreciated that it would be desirable to have a memory device that has a large number of memory blocks, thereby allowing to store a large amount of data that is not limited by the constraints mentioned above.